Is canine leptospirosis underdiagnosed in southern Ontario? A case report and serological survey

An eight-year-old city-dwelling Cairn Terrier was presented to a veterinary hospital in acute renal failure with evidence of hepatic insufficiency. The dog was treated symptomatically over three days, during which time vomiting was largely controlled, but it became jaundiced as hepatic insufficiency worsened. Leptospira pomona was demonstrated in large numbers by immunofluorescent staining of urinary sediment. It was isolated and its identity confirmed as L. pomona genotype kennewicki. The source of the infection was thought to be raccoons.

Sera from 474 blood samples submitted for diagnostic purposes to two clinical pathology laboratories in southern Ontario were examined with the microscopic agglutination test for antibodies to selected leptospiral serovars. Of the sera tested, 39.2% reacted at titers ≥1:100 with one or more serovars, the majority of all sera (26.2%) reacting at low titers to canicola or icterohaemorrhagiae, or both. These reactions likely resulted from vaccination. A smaller proportion reacted to other serovars tested: autumnalis (3.8%), bratislava (8.2%), grippotyphosa (1.9%), hardjo (3.0%), and pomona (3.2%). Among dogs reacting to these latter serovars (other than bratislava), many had broadly cross-reacting and relatively high titers. One dog with a titer of 1:800 to pomona had had a disease typical of leptospirosis two years previously. Three other dogs with high titers to autumnalis, bratislava, or mixed serovars had clinical histories compatible with leptospirosis.

We suggest that leptospiral bacterins for dogs in Ontario be broadened to include at least serovars autumnalis and pomona.

     

A preliminary assessment of association‐analysis in the Kroonstad area

Vegetation in the Kroonstad area was sampled by means of a stratified random distribution of 235 4mx4m quadrats within physiographic‐physiognomic categories as determined and delineated on aerial photographs. “Normal” and “inverse” association‐analyses were carried out “Normal” association‐analysis where low‐frequency species were, respectively, included in and excluded from the computation, gave broadly similar results in so far as the major groupings are concerned. Local frequency and constancy estimates were computed for various groupings. Association tables were drawn up for major groupings and Poore's “successive approximation” approach was adopted in reducing species associations to noda. There is a strong subjective element in this determination of noda, and an effort should be made to reduce it to a minimum.     

A preliminary report on the occurrence of maedi‐visna in sheep in Morocco

Summary

A small scale serological survey for antibodies to maedi‐visna virus among 15 flocks of sheep in Morocco revealed the infection in one flock. Infection appeared to be related with imported sheep. In addition, two abattoir surveys yielded, 0.1% lungs with gross and histological lesions suggestive of maedi.     

A history of canine parvovirus in Australia: what can we learn?

Canine parvovirus (CPV) has been reported throughout the world since the late 1970s. Published information was reviewed to draw insights into the epidemiology, pathogenesis, diagnosis, treatment and outcomes of CPV disease in Australia and the role of scientific research on CPV occurrence, with key research discoveries and knowledge gaps identified. Australian researchers contributed substantially to early findings, including the first reported cases of parvoviral myocarditis, investigations into disease aetiopathogenesis, host and environmental risk factors and links between CPV and feline panleukopenia. Two of the world's first CPV serological surveys were conducted in Australia and a 1980 national veterinary survey of Australian and New Zealand dogs revealed 6824 suspected CPV cases and 1058 deaths. In 2010, an Australian national disease surveillance system was launched; 4940 CPV cases were reported between 2009 and 2014, although underreporting was likely. A 2017 study estimated national incidence to be 4.12 cases per 1000 dogs, and an annual case load of 20,110 based on 4219 CPV case reports in a survey of all Australian veterinary clinics, with a 23.5% response rate. CPV disease risk factors identified included socioeconomic disadvantage, geographical location (rural/remote), season (summer) and rainfall (recent rain and longer dry periods both increasing risk). Age <16 weeks was identified as a risk factor for vaccination failure. Important knowledge gaps exist regarding national canine and feline demographic and CPV case data, vaccination coverage and population immunity, CPV transmission between owned dogs and other carnivore populations in Australia and the most effective methods to control epizootics.     

Characterization of β-catenin expression in canine osteosarcoma

Osteosarcoma (OSA) is the most frequently occurring malignant primary bone tumour in dogs and children and arises from cells of the osteoblast lineage. Inappropriate Wnt signalling activity has been implicated in human OSA. Altered expression of β-catenin, an integral member of the Wnt signalling pathway, has been associated with numerous human cancers, including OSA. In this study, 30 of the 37 primary canine OSA tissues and 2 of the 3 metastatic OSAs were positive for β-catenin expression as determined by immunohistochemistry, whereas 2 normal bones stained negative for β-catenin. No mutations were identified in exon 3 of β-catenin in the three OSA cases in which DNA sequencing was performed. Finally, there was no relationship between β-catenin expression and overall survival time or disease-free interval. Our results indicate β-catenin is frequently expressed within the cytoplasm of neoplastic cells in canine OSA but contains no detectable mutations in exon 3, similar to human OSA.     

Serological and parasitological survey of dourine in the Arsi–Bale highlands of Ethiopia

This study was conducted from August 2005 to January 2007 to determine prevalence and distribution of dourine in horses and to investigate the occurrence of clinical and carrier cases in donkeys and mules in the Arsi–Bale highlands. Study methodology was based on questionnaire, serological, clinical and parasitological survey. The questionnaire indicated that dourine is a major health problem of equines in the Arsi–Bale highlands. Though dourine is commonly observed throughout the year, it has a seasonal character and occurs mostly during the breeding season from June to late September. Serological screening of 646 horses showed a seroprevalence of 184 (28%), 161 (25%) and 125 (19%) for card agglutination test for trypanosomosis, LATEX and enzyme-linked immunosorbent assay, respectively. Risk factors were parity number, previous history of abortion and body condition score. No trypanosomes could be detected by Giemsa staining or by haematocrit centrifugation technique. Ten puppies inoculated with blood samples, genital washes and oedematous fluids remained parasitologically negative. Different characteristic signs of dourine were observed. During the genital stage, mares showed vaginal oedema, discharge and presence of depigmented scars over the external genitalia. In stallions, oedema of the scrotum and prepuce, prepucial and urethral discharge, and ulceration of the genital mucosae mainly of the penile were observed. In both sexes, lameness in one or both legs, partial dragging and stiffness of the hind legs and incoordination were the dominant signs observed as nervous form of the disease.     

A preliminary investigation of area‐selective grazing in the Southern Tall Grassveld of Natal

The consequences of area‐selective grazing by cattle under three stocking rates and at two sites in the Southern Tall Grassveld of Natal were investigated. Soil compaction was found to significantly distinguish area‐selected patches from non‐selected veld (P≤0.01), while non‐significant differences in soil nutrient and moisture status were recorded. Area‐selected and non‐selected patches may be distinguished on the basis of species composition. Area‐selected patches are characterized by Aristida congesta subsp. barbicollis, Microchloa caffra and Eragrostis racemosa. Non‐selected veld is characterized by Themeda iriandra, Tristachya leucothrix and Hyparrhenia hirta.     

Increase in seroprevalence of canine leptospirosis and its risk factors,Ontario 1998–2006

Canine leptospirosis has been described as having re-emerged in North America around the mid-1990s, with a change in the epidemiology of the infecting serovars responsible for the disease emergence. A retrospective case-control study was conducted to examine the re-emergence of seroprevalent cases of canine leptospirosis in Ontario using serology submission records from 1406 dogs from January 1, 1998 to December 31, 2006. The data collected [results of the microscopic agglutination test (MAT), veterinary clinic postal code, age, sex, neutering status, and breed] were analyzed by multivariable logistic regression, generalized linear mixed modeling, and Cochran-Armitage test for trends in proportions. Dogs in urban areas appeared to be at significantly higher risk than dogs in rural areas for the entire study period [odds ratio (OR) = 1.6, confidence interval (CI) = 1.2–2.3], though this was not as marked as in other studies. Results indicated that canine leptospirosis in Ontario is a disease of all breeds and ages, regardless of gender. No geographic clustering was noted, but clustering of cases by clinic within geographic areas suggested differences in awareness or in diagnosis by veterinarians. A distinctive seasonal pattern of leptospirosis, with more cases occurring during the summer and fall, as found in previous studies, was also observed in this study. The temporal trend analysis was consistent with an increasing proportion or re-emergence of seroprevalent cases of canine leptospirosis since 1998, suggesting that the putative increase in canine leptospirosis has been genuine.     

Spatial seroprevalence of bovine brucellosis in India—A large random sampling survey

Brucellosis caused by Brucella spp. is an important zoonosis and constitutes a serious public health hazard. In India, the disease is increasingly prevalent among bovine population with high zoonotic potential and negative impact on national economy. The investigation was conducted to study seroprevalence of brucellosis through random sample survey using survey tool box software. A total of 12,054 [cattle-9236, buffaloes-2818] bovine serum samples sourced from 15 states of India were tested by protein G indirect ELISA. The true prevalences of brucellosis observed in cattle and buffaloes were 8.3% and 3.6%, respectively. The highest prevalence of brucellosis was observed in the state of Punjab in both cattle and buffaloes (23.51 and 10.2%). Comparatively higher prevalence was recorded in cattle than the buffaloes in all the states except Manipur. The true prevalence greater than 5% was recorded in 8 and 3 states for cattle and buffaloes, respectively [(cattle- Punjab, Maharashtra, Rajasthan, Karnataka, Madhya Pradesh, Tamil Nadu, Gujarat and Kerala) and (buffaloes-Punjab, Gujarat and Manipur)] indicating wider prevalence of brucellosis. This study conclusively highlighted the seroprevalence of bovine brucellosis at state level which might be useful for prioritizing regions for vaccination, designing control strategies and improvisation of clinical surveillance system.     

A computed tomography–based method for the assessment of canine retrobulbar cone volume for ophthalmic anaesthesia

ObjectiveTo develop a comprehensive formula for calculating the volume of local anaesthetic solution used for retrobulbar anaesthesia in dogs with different skull morphologies.Study designRetrospective cohort imaging study.AnimalsSkull computed tomography (CT) images of 188 dogs of different breeds collected between January 2009 and December 2017.MethodsAnatomical integrity of the orbit and adjacent structures, presenting complaint, clinical signs and CT findings were verified to exclude ocular abnormalities. The volume of the retrobulbar cone of 376 eyes was calculated using CT scans of the dogs’ skulls. Additional data recorded included morphology of the skull, body weight, sex and size of the dogs, all of which were matched for possible association to the retrobulbar cone volume through univariable and multivariable linear regression models. Results of linear regression models were expressed as estimated beta coefficients with the corresponding 95% confidence intervals (95% CIs).ResultsUsing univariate analysis, the retrobulbar cone volume was positively associated with weight and male sex. In addition, brachycephalic and dolichocephalic dogs showed a larger retrobulbar cone volume than mesocephalic dogs, while sex was no longer significantly associated with the retrobulbar cone volume. In multivariate analysis, when considering all variables in the model, weight emerged as the strongest predictor (beta coefficient: 0.062 mL kg^–1, 95% CI: 0.056–0.067 mL kg^–1, p < 0.001).Conclusionsand clinical relevance In the veterinary literature, there is no agreement on the precise volume of local anaesthetic solution that should be used to achieve intraconal retrobulbar anaesthesia in dogs. Here we suggest a formula to calculate the retrobulbar cone volume and, accordingly, the injection volume of local anaesthetic solution for effective retrobulbar anaesthesia.     

Incidence of canine rabies in N'Djaména, Chad

This work describes for the first time the incidence risk of passively reported canine rabies, and quantifies reported human exposure in N'Djaména (the capital of Chad). To diagnose rabies, we used a direct immunofluorescent-antibody test (IFAT). From January 2001 to March 2002, we were brought 34 rabies cases in dogs and three cases in cats. Canine cases were geographically clustered. The annual incidence risk of canine rabies was 1.4 (95% CI: 1.2, 1.7) per 1000 unvaccinated dogs. Most of the rabid dogs were owned-although free-roaming and not vaccinated against rabies. Most showed increased aggressiveness and attacked people without being provoked. Eighty-one persons were exposed to rabid dogs and four persons to rabid cats (mostly children<15 years old). Most of the exposed persons were neighbours or family members of the animal owner. Most exposures were transdermal bites, but nearly half of all exposed persons did not apply any first wound care or only applied a traditional treatment. In N'Djaména, humans are often exposed to canine rabies but do not use the full-course post-exposure treatment and wound care is insufficient. Most rabid dogs would be accessible to parenteral vaccination. Pilot vaccination campaigns are needed to determine the success of dog mass vaccination in N'Djaména as a way to prevent animal and human rabies.     

Molecular detection of Shiga toxin–producing and antibiotic-resistant Escherichia coli isolates from buffaloes in southwest of Iran

Tropical Animal Health and Production - Three hundred fifteen bacteriological samples were obtained from feces and both external and visceral cavity surfaces of carcasses of 105 healthy buffalo...     

Evolution of canine parvovirus—A need for new vaccines?

Canine parvovirus (CPV) is a new virus, which is continuing to evolve, giving rise to new antigenic types and virus mutants that spread through the dog population. The most successful mutants, from an evolutionary perspective, appear to be selected by improved binding to the CPV receptor, the canine transferrin receptor, and by an extended host range, which for the newer antigenic types now includes both the dog and the cat. The new viruses also show antigenic differences that can be defined by binding of certain monoclonal antibodies; they also differ in their reactivity in virus neutralisation tests, using immune sera raised against the various antigenic types. These differences may influence the susceptibility of young animals to infection at the time when the level of maternally derived antibody decreases to the minimum protective titre. This minimum protective titre may vary depending on the infecting virus type. There is, however, a high degree of cross-protection between the virus types and the true relevance of the differences in neutralisation titer is currently not known.     

A preliminary investigation of the use of a foal image to reduce mare stress during mare–foal separation

The data for this study were collected from 7 mares (10 ± 1.6 years old) when their foals were 4-, 15-, 30-, 45-, or 60-days-old. On each occasion, the foals were anesthetized and placed out of sight of the mare and the mares’ behavior, heart rate, and cortisol response to foal separation in either the presence of a foal phantom, a square shape, or no visual stimuli were measured. In the presence of the foal phantom, anxious (P = 0.119) and agitated (P = 0.524) mare behavior was not significantly different from baseline values. The mares had significantly elevated behavior scores for 5 out of 6 criteria when the square phantom was presented and were significantly more active (higher scores for fidgety and active criteria) when no visual stimuli (control) were provided. Based on the data presented in this study, the use of a phantom image of a foal with neutral ear and tail position may be an effective nonchemical method of calming mares during separation from their foal.     

Are transepidermal water loss and clinical signs correlated in canine atopic dermatitis? A compilation of studies

Background – Cutaneous impairment plays a crucial role in atopic dermatitis (AD). Transepidermal water loss (TEWL) measurement is an indirect assessment of skin barrier function and correlates with disease severity in humans. Skin impairment also exists in canine AD; however, concerns exist regarding variability and reliability of TEWL measurements in dogs. Hypothesis/Objectives – The purposes of this retrospective study were twofold: first, to investigate the correlation between severity of dermatitis [measured by Canine Atopic Dermatitis Extent and Severity Index (CADESI)] and TEWL; and second, to evaluate whether increased TEWL at a young age correlates with disease severity later in life. Methods – Data from atopic beagles and dogs with natural AD were analysed. Transepidermal water loss was measured in atopic beagles (n = 24) with an open chamber and in dogs with naturally occurring AD with a closed chamber device (two studies, with n = 14 and n = 18). Pearson product–moment correlation was used for analyses. Transepidermal water loss of the inguinal region, axilla, antebrachial flexure and pinna was analysed. Correlations were investigated for each study, separately first and then jointly. They included CADESI and TEWL of individual regions, total CADESI and total TEWL of all measured regions, and total CADESI and TEWL of key regions. Results – In atopic beagles, TEWL measured at 1 year of age pre‐ and post‐allergen challenge was correlated with CADESI at 1, 3 and 6 years of age. Overall, low correlation coefficients were found; therefore, a biologically relevant connection could not be demonstrated. The main significant positive correlation was found between TEWL in the pinna and total CADESI. Conclusions and clinical importance – It is concluded that TEWL does not correlate with disease severity.     

A survey of eastern equine encephalomyelitis in Florida horses: Prevalence,economic impact,and management practices, 1982–1983

In spite of the availability of vaccines, eastern equine encephalomyelitis (EEE) virus continues to cause significant death losses in Florida horses. Veterinarians engaged in equine practice in Florida were surveyed regarding their experiences with EEE, and their responses were compared with serologic data available from the State of Florida Animal Disease Diagnostic Laboratory for 1982 and 1983. On the assumption that most cases of encephalitis in Florida are caused by EEE virus, considerable under-reporting was apparent. Clinical cases of EEE were comfirmed in every month of the year with the highest incidence observed in June and July. Northern and central Florida had the highest number of cases reported. Most deaths (78%) occurred in unvaccinated animals, indicating that greater horse owner awareness is needed. Deaths in vaccinated animals raised questions of the efficacy of current vaccines or their schedule of administration particularly in young horses. Vaccination schedule recommendations were variable between veterinarians with regard to annual versus semiannual EEE vaccination and age of first vaccination for foals. A conservative estimate of the cost to EEE to the state equine industry was greater than $1 000 000 per year.